Time Complexity

#1

How come time complexity of this snippet is O(N^2) instead of O(N) -
int sum = 0;
void calcSum(vector v, int i)
{
if(i == v.size())
return;
sum += v[i];
calcSum(v, i+1);
}

#2

hi @debhowmicksayan_df0382a1e2ea3b66,
here the vector is being passed by value so everytime u call the function vector of size n is copied and that’s happening for n times so its o(n2)

#3

So if we use vector &v then it will be O(N) right?

#4

@debhowmicksayan_df0382a1e2ea3b66 yes

#5

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